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MKTHYL OXALATK

Properties. Colourless crystals, which, on heating to 100,
lose their water of crystallisation, inch, arid then partly sublime
and partly decompose, giving off carbon dioxide and formic
acid. M. p. of the hydra.ted crystals ioi'5'J. Soluble in water
and in alcohol, very slightly soluble in ether.

Rcnctions. i. Boil a little of the acid with ammonia solution
until neutral, and add calcium chloride solution. A white pre-                  '!/

cipitate of the calcium salt is obtained, which is insoluble in                     $'

acetic acid.                                                                                                   ti i Jv

2. Add to   a  solution   of   the   acid  a  few  drops  of   dilute                    'i*

sulphuric acid, and warm gently.     On   adding  permanganate                   } '

solution it is immediately decolourised, 5(.!.,!I(.).1 + 2KMnOi+                  i   l\

^_3- Heat two or three grams of the crystals with about 5 c.c. con-                    t ^

centrated sulphuric acid.     Rapid effervescence occurs, and the                    *    (

gas maybe ignited at the mouth of the tube, C2H.>O.i I.I.,O =                    ^ 

See Appendix^ p. 257.                                     "                         >y

PREPARATION 26
CO.OCU,
Methyl Oxalate, |
CO.ocil.,
Dumas, Peligot, yf;/;/. Chim. /Yw.T 1836,58,44; Krlenmeycr,
Rep. Phann. (2), 23, 432.              '         '                                                       'M
70 grins, crystallised oxalic acid.                                            [Ki
50         (63 c.c.) methyl alcohol.                                            ^j''
f?^ j
The oxalic acid is ])owdered and healed in a. basin on a water-
bath, which is kept, boiling briskly, until no more water is given off                    1W
(one to two hours).    It must be occasionally stirred and powdered                       *j! j>
up.    It is then heated to 1 10    120 in an air-bath or in a Victor                       1A'
Meyer drying apparatus  (see  p.  27)  until  it  loses the  weight                        111
corresponding to two molecules of water.     If the Victor Meyer                    I ^
apparatus is used, amyl alcohol, b. p. 132 , should be placed in
the outer jacket.
The dehydrated and powdered oxalic acid Ls mixed with the